Brazing two metal parts together such as two tubes, one telescoped inside the other, is accomplished by heating the area of the joint between the two tubes usually by a flame from ignition of a gas/oxygen mixture and introducing a braze alloy to the area to be joined, causing the alloy to melt and form around the area to be joined. With removal of the heat the alloy will solidify and seal the joint between the two tubes. Such brazing processes have been used particularly in sealing metal tubes such as copper to steel in hermetic sealed refrigerant systems used in refrigerators and air conditioners. Because the refrigerant system is to be hermetically sealed, each of the joints must be leakproof, which requires a high quality brazing operation. In order that the surfaces to be joined will accept the brazing alloy readily, they must be free from oxide or other obstructing films. When necessary, the parts are cleaned chemically or by abrasion. It is common in many brazing operations to apply a chemical flux to the joint prior to heating the joint to prepare the surface during the heating stage so that the braze alloy will thoroughly wet the joint area and produce a good sealed joint.
One of the problems encountered in applying brazing flux to metal parts such as two metal tubes that are vertically oriented is the lack of sufficient gravitational force to distribute the flux completely around the joint which is necessary to assure a high quality brazing operation. This is particularly so when the flux is applied in an automated brazing operation which takes place on an assembly line where the flux is to be applied to the two metal tubes by automated equipment and it is not desirable to orient the tubes horizontally. Heretofore, the flux was applied by a brush being dipped into liquid flux and then dabbed onto the joint. In many cases, however, the flux would not completely cover the circumference of the joint. The brush flux application also suffers from not having a fixed amount of flux applied to the joint to assure adequate coverage.
By this invention there is provided apparatus to apply brazing flux to a joint between two vertically oriented parts which will assure that the flux covers the circumference of the joint and that a correct fixed amount of flux will be applied to the joint.